The disclosure related to polycarbonate compositions, particularly to impact modified polycarbonate compositions.
Addition of rubbery impact modifiers is commonly used to improve the toughness of aromatic carbonate polymer compositions. It is particularly desirable for impact modified polycarbonate compositions to have ductile properties below freezing temperatures (0° C.) so that the compositions may be employed in a range of temperatures and conditions. In many applications the compositions must also be flame retardant. Unfortunately, the inclusion of rubbery impact modifiers often has a negative impact on flame retardancy. Halogenated flame retardants have, in the past, provided flame retardancy without a significant negative impact on physical properties. Due to environmental concerns however it is considered important to employ flame retardants that are free of bromine and chlorine. Some commonly used flame retardants that are free of chlorine and bromine frequently must be used in amounts that have a negative impact on physical properties. Thus, the combination of flame retardancy and desirable physical properties, particularly ductility, can be difficult to achieve, especially at a thickness less than 5 millimeters (mm).
Accordingly, there is a need for an impact modified polycarbonate composition with good physical properties and flame retardancy at a thickness less than 5 mm.